Chesapeake Bay Journal: Solutions sought for excess manure piling up on farms

Solutions sought for excess manure piling up on farms

By Karl Blankenship

In the 1700s and 1800s, farmers sometimes couldn’t figure out what to do with all of the manure coming out of their animals. The waste would build up in barns until farmers would invite neighbors — usually with the inducement of plentiful alcohol — to a “dung frolic” to help clear the mess.

Others resorted to more drastic means. In 1825, one Pennsylvanian reported that “the dung has accumulated around some barns in such great quantities as to render access to them so difficult that they have been burned and new ones built.”

It was, the writer noted, more economical than shoveling manure.

The problem has not gone away. Nearly two centuries later, farmers, farm agencies and Bay cleanup advocates are trying to figure out what to do with the 44 million tons of manure produced annually by farm animals within the Bay watershed.

What happens to that mountain of manure is critical to the Bay cleanup. According to Bay Program estimates, agriculture is the largest single source of nutrients to the Chesapeake, accounting for about 38 percent of all nitrogen and 44 percent of phosphorus.

About half of all agricultural nutrients reaching the Bay are the result of animal waste, according to Bay Program estimates. And the amount of nutrients coming from manure has gradually been increasing, the figures show.

Further, those nutrients are concentrating in a few areas around the watershed, creating excesses of manure for which there is no obvious, economically feasible and environmentally safe use.

The manure problem reached the top level of the Bay cleanup effort in January when the Chesapeake Executive Council—the governors of Maryland, Virginia and Pennsylvania; the District of Columbia mayor; the EPA administrator; and the chairman of the Chesapeake Bay Commission—called for a watershedwide strategy to deal with animal waste.

The Bay Program has been coordinating a series of meetings across the watershed to get input about how manure from different livestock sectors—poultry, beef, dairy and hogs—might be dealt with in ways that would help the Bay without harming the agricultural industry.

The meetings have been well-attended. But it may take years—and significant investment—to develop enough alternative uses to absorb the watershed’s excess animal waste. “Manure management is a really tricky issue,” said Kelly Shenk, of the EPA’s Bay Program Office. “This is a problem that is not going to go away overnight.”

When the Bay Program was started in 1983, animal manure was already recognized as a threat to the Bay. It was often viewed as a waste, and often applied to the land as a means of disposal, without regard for its nutrient content. That resulted in excesses that would run off the land and pollute local streams as well as the Bay.

The “win-win” solution touted to solve the problem was nutrient management. Farmers would take into account the nutrient value of manure, apply no more than was needed to grow their crops, and save money because they would not need to buy chemical fertilizer.

Two decades later, dealing with manure has proven to be more difficult than once imagined and trends in the agricultural industry suggest the situation may get worse.

For instance:

The makeup of the animal population has shifted. Although animal populations (measured in total animal weight) have remained nearly unchanged, the poultry population has increased while dairy has declined. Pound-for-pound, chickens produce more nitrogen and phosphorus than other livestock. The result: Since the early 1980s, the total amount of nitrogen in the watershed’s animal waste has grown by 8 percent, while phosphorus has increased by 6 percent.
During the same time, the amount of farmland declined by 1.6 million acres, a 14 percent loss. That means there is less land to hold a growing amount of manure nutrients.
The number of animal operations is declining, but those that remain are becoming larger. That has the effect of concentrating large amounts of waste in local areas, creating manure “hot spots” where animal wastes exceed cropland nutrient needs.

Whereas excess manure may have been a problem for individual farms in colonial days, it now affects entire regions.

Livestock operations have increasingly concentrated in a few small geographic locations of the watershed: southcentral Pennsylvania, especially Lancaster County, which has the fifth largest animal production of any county in the nation; the Shenandoah Valley, including Rockingham County, which is the largest turkey producer in the nation and the largest dairy and chicken producer in Virginia; and the lower Delmarva Peninsula, including Sussex County, DE, which produces more chickens than any county in the nation.

An analysis by the U.S. Geological Survey shows that those areas are responsible for some of the largest amounts of nutrients reaching the Bay in the entire watershed.

To keep manure from being overapplied in such areas, state and federal regulations have increasingly required that livestock producers develop nutrient management plans. But those regulations often are less rigorous—and sometimes do not exist at all—for farms that receive animal manure, leaving the potential for overapplication.

But more, stricter regulations are coming. They are driven, in large part, by the fact that animal manure typically does not contain the same ratio of nitrogen and phosphorus as is needed by plants. When applied to meet the nitrogen needs of a crop, as has historically been the case, an excess of phosphorus accumulates in the soil—especially when phosphorus-rich poultry or hog excrement is used—greatly increasing the chance for runoff.

To prevent that from happening, state and federal regulations have gradually been shifting to require that manure be applied based on the phosphorus needs of the crop. That typically means that less manure can be used. In many cases, that will have the effect of forcing manure to be spread even thinner on croplands, creating even more excess.

“It’s going to get harder and harder,” said Doug Goodlander, of the Pennsylvania State Conservation Commission. The state adopted phosphorus-based management plans a year ago, and is developing regulations that would affect farms importing manure. “We understand that the answer to a lot of this is going to be in alternative technologies, alternative processing of manure and finding uses of manure that are nonagricultural land based.”

Indeed, a recent report from the U.S. Department of Agriculture’s Economic Research Service estimated that 60 percent of all cropland in the watershed would have to accept manure to properly distribute nutrients.

Such calculations could be simplistic. Farmers in recent years have been encouraged to adopt “no till” farming practices, which leave stubble from plants on the fields to reduce erosion. Any lands with a high potential for erosion would be a poor candidate to receive manure.

Right now, only about 10–20 percent of cropland in the Bay watershed receives manure from other farms, according to a 2003 report from the Chesapeake Bay Foundation. The reason: Although it can be a resource, it can also be a pain.

“If you are a cash grain farmer and don’t have animals, there are a number of reasons you might not be willing to accept it,” said Tom Simpson, a soil scientist with the University of Maryland and the chair of the Bay Program’s Nutrient Subcommittee.

Manure is bulky and difficult to transport—especially dairy and hog manures, which are wetter, heavier and have lower nutrient concentrations than drier, lighter poultry litter.

Nutrient content varies among manure, even from the same types of livestock, and it is more difficult to apply. Unlike commercial fertilizer, which can be placed after a crop starts growing, manure has to be applied to the land before there is any plant growth to absorb nutrients.

Manure nutrients are not as readily available for plant uptake, so more nutrients have to be applied than is the case with commercial fertilizers.

Because of the amount that has to be applied, when it has to be applied, and the ability of nitrogen to volitize out of the wastes into the atmosphere, manure nutrients are more likely to end up in the environment—and the Bay—than chemical fertilizers.

“I’ve spent 30 years of my career working on beneficial uses of organic nutrient sources,” Simpson said. “And I’ve now reached the conclusion that we can never use them as efficiently as inorganic fertilizers for either nitrogen and phosphorus.”

Nonetheless, almost everyone believes land application, where practical, must be one of the uses for manure—if for no other reason than there are not enough other potential uses. “Land application will always be an important part of this,” said Doug Parker, an agricultural economist with the University of Maryland. “I don’t think it is ‘the’ solution. There is no ‘the’ solution. Like any other economic good, there will be a bunch of different uses.”

Some believe demand for manure could get a short-term boost because of the surge in energy prices. The process of making commercial nitrogen fertilizer uses large amounts of natural gas, so the cost of nitrogen has more than doubled in the past two years as energy prices have risen.

“If energy prices stay up, it may be a positive for the Bay,” said Russ Perkinson, of the Virginia Department of Conservation and Recreation. “It is probably going to favor land application of transported poultry litter.”

Still, hauling animal waste out of areas with an excess requires subsidies in Delaware and Maryland. And that can create other problems. Some of the poultry litter is hauled to Pennsylvania, displacing manure generated there because that state does not subsidize manure transport.

Ironically, animal waste is also at a competitive disadvantage with human wastes for a place on the fields. Subsidized by sewer fees, bio-solids from wastewater treatment plants are typically hauled and applied for free, along with a treatment of lime which benefits the soil.

Many farmers are looking for the same kind of deal when accepting animal waste. “There are more people who want manure than who are trying to get rid of it, at least in terms of poultry litter,” Parker said. “But that is because the people who want manure want someone to come to their farm and put it on their fields for them, and for free.”

The bottom line, he and others say, is that as long as manure is viewed primarily as a waste, rather than a resource, economic options for manure will be difficult—and will likely require government subsidies.

Land options will be limited in the future—and not just because it will have to be spread thinner and because many farmers don’t want it. Other factors, such as increasing urbanization—suburban noses often object to manure applications—make hauling and applying manure more difficult.

“Ultimately, applying manure on agricultural land is a quick fix, but not a long-term solution,” said Shenk, of the Bay Program. “You have stricter regulations coming down, you have reduction in land, and eventually your soils are going to become phosphorus saturated,”

Increasingly, agency officials and agricultural scientists working on the Bay Program strategy to be completed this fall are looking beyond the fields for solutions to the manure nutrient problem.

The first step toward a more long-term solution, most agreed during recent meetings, is optimizing feed for animals. Controlling the amount of nutrients going in can dramatically reduce the amount being excreted. In chickens, adding the enzyme phytase has reduced the phosphorus concentrations in chicken litter by about 20 percent, and scientists believe further reductions are possible.

Feed optimization may be as close to a win-win action as exists for manure. By managing diets, farmers have the potential to save money as well as reduce nutrients in wastes.

Beyond that, solutions vary by agricultural sector, and costs become more of a factor.

Poultry litter is dry, has higher concentrations of nutrients and is easier to transport. Many see it as a prime candidate for repackaging for other uses. On the Eastern Shore, 60,000 tons of poultry litter a year are reprocessed into fertilizer pellets that are used on golf courses, sports fields and other areas. That’s not necessarily a panacea. A project in Harrisonburg, VA, that was to turn 50,000 tons of poultry litter into fertilizer failed.

During recent meetings, some suggested that the demand for processed animal manure might be increased if it replaced fertilizers used on public properties, such as highway revegetation projects. Some are suggesting that agencies set standards requiring a certain percentage of animal manure use on public lands—an idea that could find its way into the watershed manure strategy.

If more poultry litter was targeted for other uses, the farmlands that once received that waste might be able to use some of the excess dairy and hog manure, for which there are currently fewer alternative uses.

A variety of other potential uses are being practiced on a small scale, or are under serious consideration. Pennsylvania uses some manure in mine reclamation projects. Burning manure for energy is a highly touted option, and pilot projects are in various stages of development. Some is composted and resold. But many alternative uses are hampered by a variety of factors, such as transportation costs, and the need for a reliable, steady stream of manure.

Investments that lead to successful demonstration projects will be vital to maintain an agricultural industry and protect the Bay, meeting participants concluded.

“We are instituting these new regulations, but we understand that we have an obligation to try to help the industry comply with them,” said Goodlander, of the Pennsylvania State Conservation Commission. “We are not looking to try to run them out. We are looking to help them find new ways to meet these criteria.”

Manure By The Numbers

At any one time, the Bay watershed contains about 1.7 million animal units. An animal unit is 1,000 pounds of animal weight, and is equivalent to about one beef cattle, 0.7 dairy cows, 100 chickens, 55 turkeys or 2.5 hogs.
Those animals excrete about 44 million tons of manure each year.
That manure contains 595 million pounds of nitrogen and 166 million pounds of phosphorus.
About 367 million pounds of nitrogen and 91 million pounds of phosphorus is in “recoverable” manure. That is manure produced and stored in confined areas. Unrecoverable manure is generally left in pastures by free-ranging animals.
Poultry generates only 15 percent of manure by weight, but broilers excrete about 3.5 times as much nitrogen and 2.5 times the phosphorus as beef cattle. As a result, increases in the chicken population have increased nutrient concentrations in manure over the past 20 years even though the total number of animal units has stayed about the same.
Between 1982 and 2002, cropland and pastureland in the watershed declined by 14 percent, a 1.6 million acre loss.
In 1982, if all of the animal wastes were evenly applied to farmland in the watershed, it would have resulted in an average of 31 pounds of nitrogen and 10 pounds of phosphorus per acre. By 2002, those numbers would have grown to 36 pounds of nitrogen and 12 pounds of phosphorus per acre. The change reflects the loss of farmland and increased nutrient concentrations in manure.